Add another option to control output formatting of stack traces

Summary:
The current stack trace formatting is based on repeated string appends with newlines. This change adds more control so that we can produce file and line information only, without unnecessary newlines.

New format:
  ./folly/experimental/symbolizer/Symbolizer.h:77
  ./folly/experimental/symbolizer/test/StackTraceTest.cpp:209
  ./folly/experimental/symbolizer/test/StackTraceTest.cpp:213
  ./folly/experimental/symbolizer/test/StackTraceTest.cpp:258

Reviewed By: yfeldblum

Differential Revision: D21562670

fbshipit-source-id: 7d05605cbda686e2f1c87577647c7ab7581f8580

folly/experimental/symbolizer/Symbolizer.cpp

@@ -271,7 +271,7 @@ void SymbolizePrinter::print(const SymbolizedFrame& frame) {
     color(Color::DEFAULT);
   };
 
-  if (!(options_ & NO_FRAME_ADDRESS)) {
+  if (!(options_ & NO_FRAME_ADDRESS) && !(options_ & TERSE_FILE_AND_LINE)) {
     color(kAddressColor);
 
     AddressFormatter formatter;
@@ -288,13 +288,15 @@ void SymbolizePrinter::print(const SymbolizedFrame& frame) {
     return;
   }
 
-  if (!frame.name || frame.name[0] == '\0') {
-    doPrint(" (unknown)");
-  } else {
-    char demangledBuf[2048];
-    demangle(frame.name, demangledBuf, sizeof(demangledBuf));
-    doPrint(" ");
-    doPrint(demangledBuf[0] == '\0' ? frame.name : demangledBuf);
+  if (!(options_ & TERSE_FILE_AND_LINE)) {
+    if (!frame.name || frame.name[0] == '\0') {
+      doPrint(" (unknown)");
+    } else {
+      char demangledBuf[2048];
+      demangle(frame.name, demangledBuf, sizeof(demangledBuf));
+      doPrint(" ");
+      doPrint(demangledBuf[0] == '\0' ? frame.name : demangledBuf);
+    }
   }
 
   if (!(options_ & NO_FILE_AND_LINE)) {
@@ -303,17 +305,23 @@ void SymbolizePrinter::print(const SymbolizedFrame& frame) {
     fileBuf[0] = '\0';
     if (frame.location.hasFileAndLine) {
       frame.location.file.toBuffer(fileBuf, sizeof(fileBuf));
-      doPrint("\n");
-      doPrint(pad);
+      if (!(options_ & TERSE_FILE_AND_LINE)) {
+        doPrint("\n");
+        doPrint(pad);
+      }
       doPrint(fileBuf);
 
       char buf[22];
       uint32_t n = uint64ToBufferUnsafe(frame.location.line, buf);
       doPrint(":");
       doPrint(StringPiece(buf, n));
+    } else {
+      if ((options_ & TERSE_FILE_AND_LINE)) {
+        doPrint("(unknown)");
+      }
     }
 
-    if (frame.location.hasMainFile) {
+    if (frame.location.hasMainFile && !(options_ & TERSE_FILE_AND_LINE)) {
       char mainFileBuf[PATH_MAX];
       mainFileBuf[0] = '\0';
       frame.location.mainFile.toBuffer(mainFileBuf, sizeof(mainFileBuf));

folly/experimental/symbolizer/Symbolizer.h

@@ -230,6 +230,9 @@ class SymbolizePrinter {
 
     // Skip frame address information
     NO_FRAME_ADDRESS = 1 << 4,
+
+    // Simple file and line output
+    TERSE_FILE_AND_LINE = 1 << 5,
   };
 
   // NOTE: enum values used as indexes in kColorMap.

folly/experimental/symbolizer/test/StackTraceTest.cpp

@@ -20,6 +20,8 @@
 #include <folly/experimental/symbolizer/StackTrace.h>
 #include <folly/experimental/symbolizer/Symbolizer.h>
 
+#include <boost/regex.hpp>
+
 #include <glog/logging.h>
 
 #include <folly/portability/GTest.h>
@@ -172,3 +174,55 @@ TEST(StackTraceTest, FastStackTracePrinter) {
 
   testStackTracePrinter<FastStackTracePrinter>(printer, file.fd());
 }
+
+TEST(StackTraceTest, TerseStackTracePrinter) {
+  test::TemporaryFile file;
+
+  FastStackTracePrinter printer{
+      std::make_unique<FDSymbolizePrinter>(file.fd(), SymbolizePrinter::TERSE)};
+
+  testStackTracePrinter<FastStackTracePrinter>(printer, file.fd());
+}
+
+TEST(StackTraceTest, TerseFileAndLineStackTracePrinter) {
+  test::TemporaryFile file;
+
+  FastStackTracePrinter printer{std::make_unique<FDSymbolizePrinter>(
+      file.fd(), SymbolizePrinter::TERSE_FILE_AND_LINE)};
+
+  testStackTracePrinter<FastStackTracePrinter>(printer, file.fd());
+}
+
+namespace {
+constexpr int frames = 5;
+FOLLY_NOINLINE void foo(FrameArray<frames>& addresses) {
+  getStackTraceSafe(addresses);
+}
+
+FOLLY_NOINLINE void bar(FrameArray<frames>& addresses) {
+  foo(addresses);
+}
+
+FOLLY_NOINLINE void baz(FrameArray<frames>& addresses) {
+  bar(addresses);
+}
+} // namespace
+
+TEST(StackTraceTest, TerseFileAndLineStackTracePrinterOutput) {
+  Symbolizer symbolizer(LocationInfoMode::FULL);
+  FrameArray<frames> addresses;
+  StringSymbolizePrinter printer(SymbolizePrinter::TERSE_FILE_AND_LINE);
+  baz(addresses);
+  symbolizer.symbolize(addresses);
+  printer.println(addresses, 0);
+
+  // Match a sequence of file+line results that should appear as:
+  // ./folly/experimental/symbolizer/test/StackTraceTest.cpp:202
+  // or:
+  // (unknown)
+  boost::regex regex("((([^:]*:[0-9]*)|(\\(unknown\\)))\n)+");
+  auto match = boost::regex_match(
+      printer.str(), regex, boost::regex_constants::match_not_dot_newline);
+
+  ASSERT_TRUE(match);
+}